1. Field of the Invention
This invention relates to a method for producing a composite golf club head, more particularly to a method for producing a composite golf club head, which includes the step of providing an expansible pocket in the metal hollow casing of the golf club head in order to compress the bowl-shaped laminated member and thereby attach the internal wall of the metal hollow casing.
2. Description of the Related Art
In the prior art, it is advantageous that the golf club head is made of a composite material. FIG. 1 shows a conventional composite golf club head which comprises a metal hollow casing 11, a sheet of carbon fiber composite material 12, and a striking plate 13 which is made of a special alloy. The known method for producing a conventional composite golf club head comprises the steps of:
(1) forming the metal hollow casing 11 which has the outline of the golf club head, the metal hollow casing 11 further having a shaft connecting portion 111, an open top portion 115, a side wall 116, and a closed bottom portion 112 which is integrally formed with the side wall 116, the side wall 116 having a cavity 113 to which the striking plate 13 is received and fixed, a through hole 114 formed in the bottom of the cavity 113 of the side wall 116; PA1 (2) disposing a laminated member 12, which is made of a carbon fiber composite material in the metal hollow casing 11, the laminated member 12 being configured to correspondingly abut the internal wall face of the metal hollow casing 11, and having a generally flat top portion 121 fitted in the open top portion 115 of the metal hollow casing 11, in order to close the same, the laminated member 12 having a hole 122 which is aligned with the through hole 114 of the metal hollow casing 11; PA1 (3) disposing the metal hollow casing 11 in a mold; PA1 (4) extending a tube, with an elastic bag (not shown) connected to an end of the tube, into the laminated member 12 through the through hole 114 of the metal hollow casing 11 and the hole 122; PA1 (5) introducing pressurized air into the elastic bag of the tube in order to swell the elastic bag, thereby compressing the laminated member 12 to abut against the internal wall face of the metal hollow casing 11; PA1 (6) heating the metal hollow casing 11 in the mold, in order to cause the laminated member 12 to harden and attach to the internal wall of the metal hollow casing 11; PA1 (7) allowing the pressurized air to escape from the elastic bag and withdrawing the tube from the metal hollow casing 11; and PA1 (8) fixing the striking plate 13 to the cavity 113, and fixing a shaft to the shaft connecting portion 111. PA1 (1) A bulky air compressor must be prepared for supplying the pressurized air. Therefore, the total installation cost is high. PA1 (2) The through hole 114 and the hole 122 are formed adjacent to the striking face in the side wall of the composite golf club head when the process for manufacturing the composite golf club head is completed. This adversely affects the structural strength of the composite golf club head. PA1 (1) forming a metal hollow casing which has an outline of a golf club head, the metal hollow casing having a shaft connecting portion, an open top portion, a side wall, and a closed bottom portion which is integrally formed with the side wall; PA1 (2) disposing a bowl-shaped laminated member in the metal hollow casing, the bowl-shaped laminated member being made of a carbon fiber composite material, and being configured to correspondingly abut an internal wall face of the metal hollow casing, and having an open end adjacent to the open top portion of the metal hollow casing; PA1 (3) providing an expansible pocket in the bowl-shaped laminated member, the expansible pocket containing a mixture of sodium nitrite, ammonium chloride and water; PA1 (4) disposing a sheet of carbon fiber composite material over the open top portion of the metal hollow casing, in order to close the open top portion of the metal hollow casing and the open end of the bowl-shaped laminated member; PA1 (5) disposing the metal hollow casing in a mold; and PA1 (6) heating the mold to a temperature of 140.degree.-160.degree. C. in order to allow the mixture in the expansible pocket to react and produce nitrogen gas, thereby swelling the expansible pocket and forcing the bowl-shaped laminated member to attach to the metal hollow casing, and allowing the sheet of carbon fiber composite material and the bowl-shaped laminated member to harden and connect integrally to each other.
This method has the following disadvantages: